package com.hc.kafka.consumer;

import org.apache.kafka.clients.consumer.*;
import org.apache.kafka.common.TopicPartition;
import org.apache.kafka.common.serialization.StringDeserializer;

import java.time.Duration;
import java.util.*;

/**
 * 指定时间消费
 */
public class CustomConsumerSeekTime {
    public static void main(String[] args) {
        // 0 配置
        Properties properties = new Properties();

        // 连接 bootstrap.servers
        properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");

        // 反序列化
        properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());

        // 配置消费者组id
        properties.put(ConsumerConfig.GROUP_ID_CONFIG, "test");

        // 1 创建一个消费者
        KafkaConsumer<String, String> kafkaConsumer = new KafkaConsumer<>(properties);
        // 2 订阅主题 first
        List<String> topics = new ArrayList<>();
        topics.add("first");
        kafkaConsumer.subscribe(topics);

        // 指定位置进行消费
        Set<TopicPartition> assignment = kafkaConsumer.assignment();

        // 保证分区分片方案已经制定完毕
        while (assignment.size() == 0) {
            kafkaConsumer.poll(Duration.ofSeconds(1));

            assignment = kafkaConsumer.assignment();
        }

        // 希望把时间转换为对应的offset
        Map<TopicPartition, Long> topicPartitionLongMap = new HashMap<>();

        // 封装对应集合
        for (TopicPartition topicPartition : assignment) {
            // 1天前的时间
            topicPartitionLongMap.put(topicPartition, System.currentTimeMillis() - 1 * 24 * 3600 * 1000);
        }

        // 获取位移
        Map<TopicPartition, OffsetAndTimestamp> topicPartitionOffsetAndTimestampMap = kafkaConsumer.offsetsForTimes(topicPartitionLongMap);

        // 指定消费的offset
        for (TopicPartition topicPartition : assignment) {
            OffsetAndTimestamp offsetAndTimestamp = topicPartitionOffsetAndTimestampMap.get(topicPartition);
            kafkaConsumer.seek(topicPartition, offsetAndTimestamp.offset());
        }


        // 3 消费数据
        while (true) {
            ConsumerRecords<String, String> consumerRecords = kafkaConsumer.poll(Duration.ofSeconds(1));
            for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
                System.out.println(consumerRecord);
            }
        }
    }
}
